Electric switch



- Sept. 14,1926.

J. R. CARLSON ELECTRIC SWITCH Filed Sept. 27. 1924 ATTORNEYS '4 Q 4 V INVENTOR JOHnNn/ES R'.CHRLSON Patented Sept. 14, 1926.

UNITED STATES PATENT OFF ICE.

JOHANNES R. CABLSON, OF HARTFORD, CONNECTICUT, I ASSIGNOR TO THE ARROW ELECTRIC COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTI- CUT.

ELECTRIC swrrcn.

Application filed September 27, 1924. Serial No. 740,232.

My invention relates to electric switches, and particularly to rotary snap switches. The object of my invention is to provide an improved switch handle and associated parts. v

In the accompanying drawingsw Fig. 1 is a broken side elevation showing in vertical section a handle in which my invention is embodied in one form;

F ig. 2 is a' broken inverted plan of the handlebody r Fig. 3 is a droppedperspective of:certain of the handle elements; 7

Fig. 4 is a cross section of the switch spindle on the line 4-4, Fig. 1;-

Fig. 5 is a partial vertical section through the handle hub; V

Fig. 6 is a broken vertical section through the handle showing a modified form of holding nut; and

Fig. 7 is a perspective of a further modification of the nut.

In its main features the handle shown in the present drawing is closely related to that of my copending application Ser. No. 599, 506, filed November 7, 1922. Certain details of considerable practical importance have been improved.

The invention is shown applied to a switch comprising an insulating base upon which is supported the rotary switch spindle 16. The switch mechanism and contacts '(not shown) are housed as usual within I the cover 17. v r

The handle comprises an insulating button 18 recessed to form a well 19 with 'bottom pocket 20 and an annular ledge 21. Channels 22 extending the full depth of the well are provided at diametrically opposite points, while bays 23 open to the ledge 21 on opposite diameters, one of which registers with the channels 22.

The elements by which the handle is attached to the spindle 16, and by which a driving connection with the latter is established, comprise a flat nut 24 having opposite marginal lugs 25 adaptedto enter the channels 22 in the well 19. A driving plate 26, adapted to rest against the ledge 21, is

provided with similar lugs27 which enter opposite bays- 23. Freely interposed be tween the n'utQand driving plate is a coil spring '28 against thepressure of which the driving plate 26 is maintained by a split spring ring 29 sprung into an annular groove 30 spaced from the le'dge'21. A paper or fiber bearing washer 31 extends slightly beyond the inner faceof the hub 32 ofthe switch handle and is provided with marginal tongues 33 adapted to enter the several bays 23, in each of which they are engaged by gobs of cement 34.

To cooperate with the handle, the switch spindle 16 is provided at its free end with a threaded area 35 spaced from the shank of the spindle by a plain area 36 of less diameter than the threaded end and of greater longitudinal extent than the thickness of the nut 24. Spaced from the plain area 36 is a fin 37 'preferably formed integral with the spindle and reinforced against shearing strains by ribs 38 adjacent the bottom of the fin. I The driving plate 26 is centrally aperture-d at 39 to permit the threaded end of the spindle to pass freely therethrough, while a notch 40 opening to one margin of the aperture 39 is-adapted to reecive and engage the fin 37 of the spindle to establish a drive connection therewith. The nut 24 is provided with a tapped central aperture 41 adapted for engagement with the threaded end 35 of the spindle.

To assemble the handle upon the spindle in driving relation, the spindle end is passed up through a hole 39 in the driving plate 26 until it engages the nut 24. The spacing of the end of the spindle from the adjacent end of the driving fin 37 is such that an engagement may be established between the spindle and the nut before the handle is drawn down onto the spindle a sufiicient distance to bring the upper end of the fin 37 into engagement with the lower face of the driving plate 26. As I upon the spindle, however, the lower face of the plate 26 bears against the fin 37 and it is necessary to pull the buttonlS outward the handle is screwed down.

' thus establish a against the action of the spring 28 in order to hold the plate 26 clear of the fin 37 while the handle is further rotated to screw the nut 24L down on the spindle. When the nut has been turned down a certain distance on the spindle, itpruns into the neck 36 and further rotation of the handle is without other effect than to rotate the nut idly in this stripped region. The thread 35 adjacent the neck 36 now forms an abutment against which the nut is thrust by the spring 28. hen the handle is released from its outwardly drawn osition, indicated in dotted lines (Fig. 1) t e spring 28, now under increased stress, (since the nut now abuts againstt-he threaded end of the spindle) forces the handle toward the switch cover 17' and when the driving fin 37 is in register with the slot in the driving plate 26, the handle is pressed downward by the spring until the fin and plate are in driving engage- 'ment and the handle rests upon the cover 17 to hold it in position.

The limitation of the downward travel of the nut on the spindle by the neck 36 has :1m portant results. It makes it impossible to drive the spring solid between the nut and plate 2'6while the handle is raised to clear 2 the fin 37-a condition which renders it clifficult to rotate the'handle and plate to bring the slot/l0 into register with thefin' 3'7, and locked driving engagement between the handle and the spindle. Moreover the exact location of the nut in the neck 36 of the spindle insures a predetermined maximum pressure of the handle against the cover, and prevents such an over-stressing of" the spring 28 that excess friction results between the bearing washer 31 and the cover l'i a friction which increases the effort required to actuate the switch as well as increasing the wear at the handle-bearing on the cover.

"When it is desired to remove the handle from the spindle, the handle button is again lifted until the drive plate 26 clears the fin 37, whereupon reverse rotation of the handle establishes engagement between the nut and the threaded area 36. Continued rotation of the button in the same direction unscrews the nut from the spindle.

In Fig. 6 the holding nut 43 is formed from thin sheet metal which is offset or warped at the margins of the central aperture 42 to form a thread-engaging edge. From the; periphery of the nut extend outward a pair of lugs 4A which enter the chan nels 22 in the well 19 to prevent rotation of the nut with respect to the handle body. These lugs are of such length that they may be bent back to form centering fingers 45 which embrace the spindle and maintain the nut in a plane substantially normal to the spindle axis, and thus in position for re-enengagement with the thread 35 when the nut is unscrewed for the removal of the handle; (4) the reinforcement of the driving fin 37 on the spindle by means of theribs 38; (5) the use of the paper bearing washer 31; (6) the attachment of the washer by cement. j

With the understanding that the invention.

is not limited to the precise forms or proper-- tions of parts illustrated, I claim as my'invention. p i

1. A rotary snap switch handle comprising a handle body recessed to receive a. switchoperating spindle, anut slidable in said recess and adapted tosecure the handle to the spindle, in combination with a switch spindle having a threaded end adapted to' engage thenut, and an adjacentplain neck of reduced diameter upon which the nut may freely rotate after'passing the threaded endof thespindle.

2. In a rotary snap switch, a'r'otary switch spindle having a screw threaded end adapted to engage a handle nut, a portion ofthe spindle adjacent the threaded area being plain and of reduced diameter to permit the nut to swivel freely thereon after passing the threaded: end. V

3. A rotary snap switch handle'comprising a handle body recessed to receive a switch-operating spindle, a flat nut slidable in said recess and adapted to secure the handleto the spindle, in combination with a switch spindle having a threaded en'd adapted to engage the nut, and an adjacent plain neck of reduced diameter and of a length exceeding the thickness of the nut to permit the latter to swivel freely thereon after passing the threaded end of the spindle.

4. rotarysnap switch handle having a securing nut adapted to be secured'upon a threaded end of a switch spindle, together withguide fingers associated with said nut and adapted to maintain the latter in axial alignment with the spindle.

5. A rotary snap switch comprising a rotary switch spindle having a threaded end and a neck of reduced diameter adjacent said threaded end, in combination with a switch handle having an attaching nut 'adaptedlto screwnponsai'd spindle and swivel in said reduced neck region of thespindle, a spring thrusting said washer againstthe spindle 1 thread as an abutment and pressing the hanspindle having a screw threaded end and an adjacent neck of reduced diameter, a switch handle having an attaching nut adapted to screw over said spindle and to swivellingj position at said neck, and centering fingers 1 associated with said nut for holding it in a plane substantially normal to the'spindle while in swivelling position at said neck.

In testimony whereof I have signed my name to this specification.

JOHANNES R. CARLSON. 

